The Scottish Government intends to take a “coherent, consistent and collaborative approach” to its preparations for leaving the European Union, the Constitutional Relations Secretary has told MSPs.

Mike Russell said ministers would be “straight with people” as he updated Holyrood on their Brexit plans, including contingency arrangements for a no deal outcome.

However opposition parties criticised a “lack of detail” and called for more information.

While the Scottish Government has pressed for the UK to remain in the European single market and Customs Union, Mr Russell said it “has always made a distinction between the politics of Brexit and the absolute necessity of doing everything we can to ensure no legislative cliff-edge”.

“The Scottish Government intends to take a coherent, consistent and collaborative approach to making preparations for EU exit,” he added.

“We will be straight with people.”

He said “legislative heavy lifting” would be required to ensure Scottish laws are prepared for Brexit.

“The deficiencies in our statute book that have already been identified – the areas where change must be made – are many and varied,” he said.

“We need to correct hundreds of pieces of legislation, not a mere handful. But we have no choice.”

Up to 200 pieces of legislation may need to pass through Holyrood, Mr Russell said.

“That’s a heavy burden – it could be heavier still if Westminster is not willing to co-operate sensibly,” he added.

Meanwhile £27 million of additional funding will be used to prepare areas with “specific EU-exit related demands”, and civil contingency planning is taking place in areas where a no-deal outcome could have an “immediate and direct effect on citizens”.

The UK Government has already published a series of technical notices designed to prepare the UK for the possibility of a no-deal Brexit.

Mr Russell added: “After the next two tranches of technical notices are issued we will consider publishing our own supplementary guidance if we feel it can be useful, and if it does not add to the momentum around a no deal, which could be an unforeseen outcome.”

He continued: “However carefully we prepare for a no deal scenario, it will still result in chaos.

“Even the UK Government’s own no deal plans will require a plethora of agreements with the EU in order to work effectively.

“In a situation where negotiations have broken down, we have to ask how plausible this is.”

Scottish Labour’s Brexit spokesman Neil Findlay said he had “serious concerns about the lack of detail” on the government’s planning, and called on Mr Russell to set out the exact progress in each sector.

“With the Tories becoming ever more factional by the day and the Chequers deal sinking, it is right that the Scottish Government prepares for every scenario,” he said.

“But the reality is the SNP has provided scant detail on the nature of its preparations, focusing instead on spin and rhetoric over substance.”

Green co-convener Patrick Harvie also urged the government to provide more information to “reassure” the public.

Conservative Adam Tomkins said: “What we need from Scottish ministers is not more empty posturing on Brexit, which is all we were just treated to from Mike Russell, but constructive engagement in the work of co-operating with the UK Government to secure the best possible Brexit deal for Scotland and for all of the UK.”